I'm with the other ladies, I really don't know what you would make with pregnancy related fabric that would be something you'd really use or want after it was all over. None of those fabrics look like anything you'd want a shirt made out of and that's the only thing I can think of that you use much different during pregnancy. Maybe some pj pants?
As for the phrase "knocked up", it doesn't carry a real positive connotation in my opinion. If someone were to refer to me as being "knocked up" when I was pregnant, I would of taken offense.